In the process of trying to track down a potential bug altering theregistered arch for a syscall rule, I propose this simplification ofstruct audit_krule that removes an unnecessary member.

The arch_f pointer was added to the struct audit_krule in commit:e54dc2431d740a79a6bd013babade99d71b1714f ("audit signal recipients")

This is only used on addition and deletion of rules which isn't timecritical and the arch field is the first field if it is present at all,easily found iterating over the field type. This isn't worth theadditional complexity and storage. Delete the field.